The latter observation may explain a common folk etymology of the
term; that it came from telephone company usage, in which "bugs in a
telephone cable" were blamed for noisy lines. Though this derivation
seems to be mistaken, it may well be a distorted memory of a joke
first current among telegraph operators more than a century ago!

It seems to me that nobody really knows and that it's just a reference that came into being maybe through another domain than software and eventually creeped into it when computers and software were born. I've always thought that it might have been because an actual bug (insect) went into a mechanical calculator and got jammed somewhere which messed the process.

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I've always suspected that it's no coincidence that "bug" and "virus", two computer terms referring to something wrong in a system, mean the same thing medically.
– JeremySep 7 '11 at 3:57

4

@Jeremy "Bug" and "virus" have radically different meanings in software, though. Bugs are simply unintentional defects in software; viruses are software specifically designed to copy itself from system to system without the user's knowledge.
– benzadoSep 7 '11 at 5:21

1

You misread the Wikipedia article; the Ada Byron quote demonstrates the concept of a 'bug', but it's the Edison quote from 1878 that uses the word.
– Russell BorogoveSep 7 '11 at 18:57

Just a comment about the "joke" among old-time telephone operators that bugs were messing up the lines - they were - they would bore holes in the lead-sheathed splice boxes of the old cable systems. lead cable borer
– Phil SweetJun 7 '17 at 2:14

4 Answers
4

The story I've always heard was that Adm. Grace Hopper coined the term "debugging" when a moth was removed from the computer she was working on. Here's a link to Adm. Hopper's bio, including a picture of the notebook page in which the first bug was immortalized:

Update: Wikipedia shows the same picture, and says that "bug" and "debug" were in use before the "first actual computer bug." Wikipedia's version of the etymology of "bug" says that the term had been in use in engineering for decades before the taping of the moth, and that the moth was taped into the notebook because those who found it knew the term's meaning in engineering. That seems to make more sense -- taping an actual moth into the log book would have been more gross than funny had the term "bug" not already been familiar to those in the group. In my own experience, Adm. Hopper's name has been associated with "bug" every time I've heard or read this story, probably because she often told the story herself. So, while she apparently did not coin the term, I think she deserves significant credit for cementing "bug" in the programmer's daily lexicon.

The question is about the origin of the word "bug" in software. The thing is, the term was already used, as the note reads: "first actual case".
– NikkoSep 7 '11 at 5:55

3

-1 Most of this answer is about "debugging". The answer doesn't even mention Wikipedia's etymology, and in any case that's not a good enough source. If you read the Wikipedia etymology it even says: "The invention of the term "bug" is often erroneously attributed to Grace Hopper". It doesn't even give an etymology of bug in software.
– HugoSep 7 '11 at 8:23

3

What I meant is chances are this incident had no impact in the popularization of the usage of "bug" in softwares
– NikkoSep 7 '11 at 9:36

Use of bug in the general sense of a disruptive person is in Shakespeare Henry VI, part III - Act V, Scene II: King Edward:
“So, lie thou there. Die thou; and die our fear; For Warwick was a bug that fear'd us all.”

Samuel Johnson's dictionary defines bug as “A frightful object; a walking spectre” from ‘bugbear’, a Welsh term for a mythological monster

The earliest use in the software sense seems to be Edison:

... Edison in the year 1889: In that year, the Pall Mall Gazette reported that "Mr. Edison...had been up the two previous nights discovering a 'bug' in his phonograph—an expression for solving a difficulty, and implying that some imaginary insect has secreted itself inside and is causing all the trouble."

The stories about finding bugs in vacuum tubes and never seemed quite convincing; I suspect the better question is to ask about the origin of "bug" in engineering (going back further than computers).
– benzadoSep 7 '11 at 5:23

6

@benado - the point of the Grace Hopper 'bug' was that the term was already common enough to be ironic
– mgbSep 7 '11 at 5:49

1

Yeah, I got that. It clearly it came to software from engineering, and to engineering from, well, Shakespeare. So I'm saying I'm more interested in the early engineering uses.
– benzadoSep 7 '11 at 5:59

2

I understand that what I am interested in isn't what you asked. The path of "bug" from the engineering realm and the software realm is pretty clear to me (both mean a defect). The path from "walking spectre" to engineering defect is a little more interesting (to me). You don't need to clarify your question (J_A_X) or your answer (Martin), I get them, I was just making a comment.
– benzadoSep 7 '11 at 6:20

1

@J_A_X The Harvard Mark II read programs from tape (the "software") and executed it using those relays (or switches, like in a processor). Anyway, regardless of software/hardware nit-picking, it's certainly a nice story :)
– HugoSep 7 '11 at 9:03

Admiral grace hopper (an early computing pioneer better known for
inventing cobol) liked to tell a story in which a technician solved a
glitch in the harvard mark ii machine by pulling an actual insect out
from between the contacts of one of its relays, and she subsequently
promulgated bug in its hackish sense as a joke about the incident
(though, as she was careful to admit, she was not there when it
happened). For many years the logbook associated with the incident and
the actual bug in question (a moth) sat in a display case at the Naval
Surface Warfare Center (NSWC). The entire story, with a picture of the
logbook and the moth taped into it, is recorded in the "Annals of the
History of Computing", Vol. 3, No. 3 (July 1981), pp. 285--286.

The text of the log entry (from September 9, 1947), reads "1545 Relay
#70 Panel F (moth) in relay. First actual case of bug being found".
This wording establishes that the term was already in use at the time
in its current specific sense - and Hopper herself reports that the
term "bug" was regularly applied to problems in radar electronics
during WWII.

Indeed, the use of "bug" to mean an industrial defect was already
established in Thomas Edison's time, and a more specific and rather
modern use can be found in an electrical handbook from 1896 ("Hawkin's
New Catechism of Electricity", Theo. Audel & Co.) which says: "The
term "bug" is used to a limited extent to designate any fault or
trouble in the connections or working of electric apparatus." It
further notes that the term is "said to have originated in quadruplex
telegraphy and have been transferred to all electric apparatus."

The latter observation may explain a common folk etymology of the
term; that it came from telephone company usage, in which "bugs in a
telephone cable" were blamed for noisy lines. Though this derivation
seems to be mistaken, it may well be a distorted memory of a joke
first current among telegraph operators more than a century ago!

Actually, use of "bug" in the general sense of a disruptive event goes
back to Shakespeare! In the first edition of Samuel Johnson's
dictionary one meaning of "bug" is "A frightful object; a walking
spectre"; this is traced to "bugbear", a Welsh term for a variety of
mythological monster which (to complete the circle) has recently been
reintroduced into the popular lexicon through fantasy role-playing
games.

As for "debugging", wikipedia notes that the Oxford English Dictionary entry for "debug" contains a use of "debugging" in the context of air-plane engines in 1945.

For the use of "bug" in software, then, at first in the history of computers there was no real software, the program was hardcoded with hardware parts. So it seems sensible to say that the term transitioned from hardware to software when the latter started to be independant from the former..

EDIT

I found in Robert Leckie's book "Strong Men Armed: The United States Marines Against Japan" that he refers to a "faulty" airplane as "a plane full of bugs". I think it was then a Navy/Marine expression at that time (the book was written in 1962 though).

The earliest evidence of "bug" being used in the context of a computer (and in software) was on 17th April 1944, pre-dating the famous 1947 moth found in the Harvard Mark II.

The ASCC Mark I arrived at Harvard in February of 1944 and was
installed with the assistance of IBM engineers (see Fig. 2 ). I.B.
Cohen has examined a photocopy of the logbook kept by Robert Campbell,
a young physicist at the Computation Laboratory. It tersely summarizes
hours spent finding and correcting errors. On 17 April 1944, Campbell
wrote, "Ran test problem. Mr. Durfee from I.B.M. was here to help us
find 'bugs.'"